Device for evaluation of fluids using electromagnetic energy

ABSTRACT

A portable, tabletop fluid sampling device simplifies spectral analysis to produce an accurate but inexpensive chromatic fingerprint for fluid samples. In one embodiment, the sampling device uses an array of variable wavelength LED emitters and photodiode detectors to measure Rayleigh scattering of electromagnetic energy from the fluid sample contained in a cuvette. Either the fluid itself, or particles suspended in the fluid can then be identified by performing spectral pattern matching to compare results of a spectral scan against a library of known spectra. A wide range of applications include substance identification, security screening, authentication, quality control, and medical diagnostics.

BACKGROUND

1. Field

This disclosure generally relates to evaluation systems, and moreparticularly to systems that evaluate characteristics of substancesusing electromagnetic energy.

2. Description of the Related Art

Various systems employ spectral analysis returned from a sample of asubstance to analyze the sample and/or recognize the substance.

For example, U.S. Pat. No. 8,076,630 describes systems and methods ofevaluating objects using electromagnetic energy. In particular, U.S.Pat. No. 8,076,630 teaches a system for evaluating subject objects, thesystem which includes at least one physical source operable to emitelectromagnetic energy and driver electronics drivingly coupled to atleast one physical source. The driver electronics drive at least onephysical source as a number of logical sources, using an electromagneticforcing function where the number of logical sources is greater than thenumber of physical sources. In addition, the system includes a sensor toreceive an electromagnetic response from at least a portion of anevaluation object illuminated by one or more physical sources operatedas logical sources, and convert the electromagnetic response to a testresponse signal indicative of the electromagnetic response of theevaluation object.

Also for example, U.S. Pat. No. 7,996,173 describes methods, apparatusand articles to facilitate distributed evaluation of objects usingelectromagnetic energy. In particular, U.S. Pat. No. 7,996,173 teachesthat objects such as manufactured goods or articles, works of art, mediasuch as identification documents, legal documents, financialinstruments, transaction cards, other documents, and/or biologicaltissue are sampled via sequential illumination in various bands of theelectromagnetic spectrum, and a test response to the illumination isanalyzed with respect to reference responses of reference objects. U.S.Pat. No. 7,996,173 teaches that the sequence may be varied. Forinstance, the sequence may define an activation order, a drive leveland/or temperature for operating one or more sources. Illumination maybe in visible, infrared, ultraviolet, or other portions of theelectromagnetic spectrum. U.S. Pat. No. 7,996,173 further teaches thatelements of the evaluation system may be remote from one another, forexample communicatively coupled via a network.

As a further example, U.S. Pat. No. 8,081,304 describes the use ofspectral information in process control and/or quality control of goodsand articles. In particular, U.S. Pat. No. 8,081,304 describes the useof spectral information in process control and/or quality control ofmedia, for example financial instruments, identity documents, legaldocuments, medical documents, financial transaction cards, and/or othermedia, fluids for example lubricants, fuels, coolants, or othermaterials that flow, and in machinery, for example vehicles, motors,generators, compressors, presses, drills and/or supply systems. U.S.Pat. No. 8,081,304 further describes the use of spectral information inidentifying biological tissue and/or facilitating diagnosis based onbiological tissue.

The above described patents are only representative.

BRIEF SUMMARY

It may be useful to analyze fluids, in particular, to determine variousphysical characteristics of the fluids and/or to recognize the fluid ascarrying or not carrying a specific type of substance. In order toreliably analyze and/or recognize a fluid or a substance within thefluid, it may be useful to sample the fluid at a relatively large numberof distinct wavelengths or bands of wavelengths of electromagneticenergy. The wavelengths may for example include some or all wavelengthsin an optical portion of the electromagnetic spectrum, fromnear-infrared (N-IR) to near-ultraviolet (N-UV), inclusive, including avisible portion that is visually perceptible to humans. Accuratelyperforming such analysis or recognition typically requires a relativelylarge number of distinct sources or emitters, e.g., solid-state sourcesof electromagnetic energy such as light emitting diodes (LEDs), eachoperable to emit electromagnetic energy in a respective range or band ofwavelengths which may or may not partially overlap with one another.

To achieve a high degree of reliability it may be advantageous toperform calibration. Calibration can address issues raised by variationsin source performance, for example variations in emitter wavelengthoutput due to age, changes in temperature, or even in manufacturingtolerances (e.g., from batch to batch from a given emittermanufacturer). However, to be effective calibration will typically needto be performed automatically, preferably with little to no user oroperator interaction. Also, to be effective calibration with respect tosources or emitters should employ calibration targets or samples withknown characteristics (e.g., spectral characteristics) which are stableand do not vary over time.

Providing for automatic calibration may enhance the accuracy of samplingdevices. Providing for automatic calibration in a compact form factormay further allow for small, portable sampling devices, which are highlyaccurate.

Scattering is a physical process in which some forms of electromagneticenergy deviate from a straight path or trajectory due to localizednon-uniformities in a medium through which the electromagnetic energypasses. As commonly used, this also includes deviation of reflectedelectromagnetic energy from an angle predicted by the law of reflection.Reflections that undergo scattering are often called diffusereflections, while unscattered reflections are called specular (e.g.,mirror-like) reflections.

Electromagnetic scattering mechanisms include, for example, Rayleighscattering and Raman scattering. In Rayleigh scattering most photons areelastically scattered such that the scattered photons have the samekinetic energy, and therefore the same wavelength, as the incidentphotons. In Raman scattering, photons are scattered by excitation, sothat the scattered photons have a frequency that is different from, andusually lower than, that of the incident photons. For any given sampleboth mechanisms will typically apply, with Raman scattering making up asmaller fraction of the total scattering. Raman scattering isparticularly useful in analyzing composition of liquids, gases andsolids.

Lambertian reflectance characterizes an ideal diffusely reflectingsurface. An apparent brightness of such an ideal diffusely reflectingsurface is the same regardless of angle of view. Technically, theluminance of a surface is isotropic, and luminous intensity obeysLambert's cosine law. Lambertian reflection from polished (i.e., glossyor non-matte) surfaces is typically accompanied by specular reflection.The luminance of a polished or glossy surface is largest when viewed ata perfect reflection direction, for example, normal to the surface(i.e., where a direction of the reflected light is a reflection of thedirection of the incident light in the surface). The luminance falls offsharply as direction (i.e., angle) changes.

An undisturbed surface of a liquid exhibits specular (mirror-like)reflection. To achieve a high degree of accuracy, in someimplementations it may be advantageous to eliminate specular reflectionor at least allow discrimination between scattered and specularreflection. Such reflection may be from a sample or specimen itself, asurface on which the sample or specimen resides, or even a component ofa sampling device, for instance a protective window or lens cover. Toachieve a high degree of accuracy, in some implementations it may beadvantageous to separate specular reflection from diffuse reflection,detecting each separately.

Sampling devices employing automatic calibration and/or separation ofspecular reflection may be effective employed in the object analysis,evaluation or identification to various applications, for example:manufacturing process control, quality assurance, media authentication,biological tissue recognition, identification, verification,authentication, classification, and/or diagnostics.

A sampling device may be summarized as including a housing; a samplechamber in the housing, the sample chamber sized and dimensioned toreceive a sample cuvette at least partially therein, the sample chamberhaving at least one opaque wall and at least a first aperture and asecond aperture positioned at least partially across at least a portionof the sample chamber from the first aperture, the first and the secondaperture transmissive of electromagnetic energy of at least somewavelengths in an optical portion of the electromagnetic spectrum; aplurality of emitters received in the housing, each of the emittersselectively operable to emit electromagnetic energy in a respectiverange of wavelengths toward and through the first aperture of the samplechamber, the ranges of wavelengths of at least some of the emittersdifferent from the ranges of wavelengths of others of the emitters; atleast one primary sampling sensor positioned to receive electromagneticenergy emitting from the sample chamber via the second aperture; and atleast one calibration sensor positioned to receive electromagneticenergy emitted by at least one of the emitters, substantially free ofelectromagnetic energy emitting, if any, from the sample chamber.

The sampling device wherein there may be formed a slit in a calibrationprinted circuit board (PCBA) opposed to the emitters, and the at leastone calibration sensor may include at least a first calibration sensorpositioned to one side of the slit and at least a second calibrationsensor positioned to another side of the slit, the other side of theslit disposed across the slit from the first side of the slit. Theemitters may all be aligned with the first aperture. The at least onecalibration sensor may be positioned at least adjacent a first portionof the sample chamber opposed to the emitters. The emitters may becarried by an emitter circuit board, the emitter circuit board spacedfrom the sample chamber opposed to the first aperture. At least one ofthe primary sampling sensors may be carried by a direct sensor circuitboard, the direct sensor circuit board spaced from the sample chamberopposed to the second aperture. The sample chamber may include a thirdaperture, the third aperture positioned at least partially across thesampling chamber from both the first and the second apertures, and theat least one primary sampling sensor may include at least a firstprimary sampling sensor positioned to receive electromagnetic energyemitting from the sampling chamber via the second aperture and at leasta second primary sampling sensor positioned to receive electromagneticenergy emitting from the sampling chamber via the third aperture. Thesecond aperture may be diametrically opposed across the sample chamberfrom the first aperture and the third aperture may be non-collinear withan optical axis that extends between the first and the second apertures.The third aperture may be positioned along an axis perpendicular to theoptical axis that extends between the first and the second apertures.The emitters may be carried by an emitter circuit board, the emittercircuit board spaced from the sample chamber opposed to the firstaperture, at least the first primary sampling sensors may be carried bya direct sensor circuit board, the direct sensor circuit board spacedfrom the sample chamber opposed to the second aperture, and at least thesecond primary sampling sensors may be carried by an indirect sensorcircuit board, the indirect sensor circuit board spaced from the samplechamber opposed to the third aperture to capture electromagnetic energyscattered from the sample chamber. The sampling device may furtherinclude a biasing member such as, for example, a spring that biases atleast the sample cuvette outwardly from the housing. The respectiveranges of wavelengths of at least two of the emitters may at leastpartially overlap. The sampling device may further include the samplecuvette sized and dimensioned to be at least partially received by thesample chamber, at least a portion of the sample cuvette transmissive toat least some of the wavelengths of electromagnetic energy emitted bythe emitters. The optical portion of the electromagnetic spectrum mayextend from near-infrared through near-ultraviolet. The sampling devicemay further include at least one port providing flow through fluidcommunication with the cuvette. The sampling device may further includeat least one control subsystem communicatively coupled to the emitters,the primary sampling sensors; and the calibration sensors; and at leastone temperature sensor communicatively coupled to the at least onecontrol subsystem, wherein the at least one control subsystem controlsoperation based at least in part on information from both thecalibration sensors and the at least one temperature sensor. The atleast one control subsystem may calibrate an output value based at leastin part on information from both the calibration sensors and the atleast one temperature sensor. The at least one control subsystem maycalibrate a drive signal supplied to at least one of the emitters basedat least in part on information from both the calibration sensors andthe at least one temperature sensor.

A sampling device may be summarized as including a housing; a samplechamber in the housing, the sample chamber sized and dimensioned toreceive a sample cuvette at least partially therein, the sample chamberhaving at least one opaque wall and at least a first aperture, a secondaperture positioned at least partially across at least a portion of thesample chamber from the first aperture, and a third aperture, the thirdaperture positioned at least partially across the sampling chamber fromboth the first and the second apertures, the first, the second, and thethird apertures transmissive of electromagnetic energy of at least somewavelengths in an optical portion of the electromagnetic spectrum; aplurality of emitters received in the housing, each of the emittersselectively operable to emit electromagnetic energy in a respectiverange of wavelengths toward and through the first aperture of the samplechamber, the ranges of wavelengths of at least some of the emittersdifferent from the ranges of wavelengths of others of the emitters; atleast one direct primary sampling sensor positioned to receiveelectromagnetic energy emitting from the sampling chamber via the secondaperture and not by the first or the third apertures; and at least oneindirect primary sampling sensor positioned to receive electromagneticenergy emitting from the sampling chamber via the third aperture and notby the first or the second apertures.

The second aperture may be diametrically opposed across the samplechamber from the first aperture. The third aperture may be non-collinearwith an optical axis that extends between the first and the secondapertures. The third aperture may be perpendicular to an optical axisthat extends between the first and the second apertures. The emittersmay be carried by an emitter circuit board, the emitter circuit boardspaced from the sample chamber opposed to the first aperture, at leastthe first primary sampling sensor may be carried by a direct sensorcircuit board, the direct sensor circuit board spaced from the samplechamber opposed to the second aperture, and at least the second primarysampling sensor may be carried by an indirect sensor circuit board, theindirect sensor circuit board spaced from the sample chamber opposed tothe third aperture to capture electromagnetic energy scattered from thesample chamber. The sampling device may further include at least onecalibration sensor positioned to receive electromagnetic energy emittedby at least one of the emitters, substantially free of electromagneticenergy emitting, if any, from the sampling chamber. The sampling devicemay further include at least one control subsystem communicativelycoupled to the emitters, the primary sampling sensors; and thecalibration sensors; and at least one temperature sensor communicativelycoupled to the at least one control subsystem, wherein the at least onecontrol subsystem controls operation based at least in part oninformation from both the calibration sensors and the at least onetemperature sensor. The at least one control subsystem may calibrate anoutput value based at least in part on information from both thecalibration sensors and the at least one temperature sensor. Thesampling device may further include a biasing member that biases atleast the sample cuvette outwardly from the housing. The respectiverange of wavelengths of at least two of the emitters may at leastpartially overlap. The sampling device may further include the samplecuvette sized and dimensioned to be at least partially received by thesample chamber, at least a portion of the sample cuvette transmissive toat least some of the wavelengths of electromagnetic energy emitted bythe emitters. The optical portion of the electromagnetic spectrum mayextend from near-infrared through near-ultraviolet. The sampling devicemay further include at least one port providing flow through fluidcommunication with the cuvette.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative positions of elements in the drawingsare not necessarily drawn to scale. For example, the shapes of variouselements and angles are not drawn to scale, and some of these elementsare arbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn, are notintended to convey any information regarding the actual shape of theparticular elements, and have been solely selected for ease ofrecognition in the drawings.

FIG. 1 is an isometric view of the exterior of a fluid sampling devicewith a hinged lid in the fully open position, according to oneillustrated embodiment.

FIG. 2 is a pictorial perspective view of the exterior of a fluidsampling device with a hinged lid in the closed position, according toone illustrated embodiment.

FIG. 3 is a top plan view of the exterior of a fluid sampling deviceaccording to one illustrated embodiment.

FIG. 4 is a bottom plan view of the exterior of a fluid sampling deviceaccording to one illustrated embodiment.

FIG. 5 is a side elevation view of the exterior of a fluid samplingdevice, in which a communications port is shown, according to oneillustrated embodiment.

FIG. 6 is a top perspective view of a parts assembly shown removed fromthe housing of a fluid sampling device, according to one illustratedembodiment.

FIG. 7 is a top plan view of the parts assembly of the fluid samplingdevice of FIG. 6 shown relative to the housing, in which propagationpaths of incident and scattered electromagnetic energy are indicated bya ray diagram.

FIG. 8 is a pictorial perspective view of a sample chamber within afluid sampling device, according to one illustrated embodiment.

FIG. 9 is an isometric view of the parts assembly of FIG. 6, shownrelative to the sample cuvette.

FIG. 10 is an isometric view of the parts assembly shown in FIG. 9,relative to the sample chamber, according to one illustrated embodiment.

FIG. 11 is an isometric view of the parts assembly of the fluid samplingdevice of FIG. 6, shown relative to the sample cuvette, in which emitterchips are shown mounted on the emitter printed circuit board assemblyand sensor chips are shown on the backplane.

FIG. 12 is an interior side elevation view of one embodiment of a fluidsampling device, in which propagation paths of incident and scatteredelectromagnetic energy are indicated.

FIG. 13 is an isometric view of a sampling system that includes one ormore fluid sampling devices and one or more processor-based devices towhich the fluid sampling devices are communicatively coupled, accordingto one illustrated embodiment.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various disclosedembodiments. However, one skilled in the relevant art will recognizethat embodiments may be practiced without one or more of these specificdetails, or with other methods, components, materials, etc. In otherinstances, well-known structures associated with computing systems,networks, servers, microprocessors, memories, buses, sources ofelectromagnetic energy, and/or detectors or sensors have not been shownor described in detail to avoid unnecessarily obscuring descriptions ofthe embodiments.

Unless the context requires otherwise, throughout the specification andclaims which follow, the word “comprise” and variations thereof, suchas, “comprises” and “comprising” are to be construed in an open,inclusive sense, that is as “including, but not limited to.”

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

The headings and Abstract of the Disclosure provided herein are forconvenience only and do not interpret the scope or meaning of theembodiments.

The ability to recognize, identify, verify, authenticate and/or classifyobjects has numerous commercial applications.

It may be useful to determine analyze characteristics of a sample orspecimen being evaluated. For example, it may be useful to determinewhether a sample or specimen being evaluated is identical or similar toa previously evaluated sample or specimen, for instance a referencesample or specimen. Also for example, it may be useful to determine if asample or specimen is identical to a previously evaluated sample orspecimen.

Referring to FIGS. 1 and 2, a fluid sample or specimen analysis orevaluation device 100 is shown according to one illustrated embodiment,referred to herein simply as sampling device 100. Types of fluids thatcan be accommodated by the sampling device 100 include liquids, andhighly viscous materials such as gels, slurries, pastes, and the like.Liquids include pure liquids and liquids containing particulates suchas, for example, colloidal suspensions. Some examples of the samplingdevice 100 can accommodate other types of fluid samples such as aerosolsor other suspensions of liquid droplets or solid particles in a gas(e.g., sprays). Other examples of the sampling device 100 can includegases themselves (pressurized or un-pressurized (e.g., air, oratmospheric samples). However, because the sampling device 100 may beused more often to analyze liquids, the sampling device 100 can bereferred to as a liquid scanner.

As discussed in detail below, the sampling device 100 is operable tosequentially illuminate a fluid sample with a number of bands ofelectromagnetic energy. The sampling device 100 is also operable todetect, measure or otherwise capture electromagnetic energy reflected,emitted, fluoresced, refracted, diffracted or otherwise transmitted, orotherwise returned from the fluid sample in response to theillumination. As used herein and in the claims, the terms illuminate,illuminates, illumination, and variations of such terms mean to exposeto or reveal by the use of electromagnetic energy or electromagneticenergy, whether in the visible portion of the electromagnetic spectrum,the optical portion (e.g., visible, near-infrared, near-ultraviolet), orother portions (e.g., far-infrared, far-ultraviolet, microwave, X-ray,etc.).

The sampling device 100 includes a housing 102 which, in the illustratedembodiment, includes a tubular (e.g., cylindrical) main body housingportion 102 a, a sample chamber 102 b in the main body housing portion102 a, and a cap 102 c having a top surface 104. The housing 102 may,for example, be sized and dimensioned as a portable tabletop unit thatcan be hand carried from one location to another. Furthermore, such atable top unit is intended to be accessible and affordable to a widerrange of users than are existing laboratory-based models.

The main housing portion 102 a has a housing base 106 a and a housingtop 106 b opposite the housing base 106 a. The main housing portion 102a has a side wall 108 surrounding the sample chamber 102 b which isadjacent to an exterior surface of the main housing portion 102 a. Thetop end 106 b can be exposed by opening exemplary hinged lid 117 toprovide selective access to the sample chamber 102 b. The main housingportion 102 a may be comprised of any of a large variety of materials,for example ABS plastic, other plastics, metals (e.g., aluminum) and/orcomposite materials (e.g., carbon fiber impregnated resin). The mainbody housing portion 102 a may be sized and dimensioned to be easilyheld and operated by a person using a single hand. While illustrated asa cylinder, the main body housing portion 102 a may take any variety ofshapes.

The sampling device 100 may also include one or more function buttons110 which are operable from an exterior of the sampling device 100, forexample, from the cap 102 c. The function buttons 110 may take any of alarge variety of forms, other than push-buttons, (e.g., slideableswitches, rotatable selectors, and the like). For example, a contact orslideable switch may be actuatable via a window, slot or other aperturein the housing 102. Additionally or alternatively, a touch sensitiveswitch may be employed, for instance an inductive or a capacitiveswitch. The function buttons 110 may be responsive to actuation to senda signal, or otherwise cause the sampling device to execute a samplingoperation. As discussed in detail below, the sampling operation may bepreceded by a calibration operation.

The sampling device 100 may further include one or more visualindicators (e.g., light emitting diodes or LEDs, two shown collectivelyreferenced as 112), shown in FIGS. 1, 2 as located on an upper surface104 of the cap 102 c. The visual indicators 112 may indicate a status ormode of the sampling device (e.g., “ready” or “power on”), for instancevia different colors (e.g., green, red, amber) and or patterns (e.g.,flashes). Or, one or more light communicative paths (e.g., optical fiberor light pipes) may communicatively couple light to the visualindicators 112. Additionally or alternatively, visual indicators 112 maybe located anywhere on the housing 102, or underneath a window (notshown) mounted anywhere on the surface of the housing 102.

The sample chamber 102 b is sized and dimensioned to at least partiallyreceive, as shown in FIG. 1, a specimen container referred to as asample cuvette 114. The sample cuvette 114 may be made of any of a largevariety of materials transmissive (i.e., transparent or at leasttranslucent) to at least those wavelengths of electromagnetic energy(e.g., UV) which are used in the analysis or evaluation of a sample orspecimen. Such materials may include, for example, silica (i.e., fusedquartz) or a cyclic polyolefin commercially available from ZeonChemicals of Louisville, Ky. under the trademark Zeonex®, for examplehaving minimal absorption characteristics for wavelengths betweenapproximately 330 nm and extending to or beyond approximately 1,200 nm.Material transparency may vary with the choice of wavelengths used forillumination. In addition, containment of different fluids may requiredifferent materials. A plurality of different cuvette types maytherefore be accommodated by the sampling device 100. While illustratedas a square cylindrical tube, the sample cuvette 114 and sample chamber102 b may take any variety of shapes. An advantage of the squarecylindrical tube is the avoidance of focusing, refracting, ordiffracting certain electromagnetic wavelengths. The sampling device 100can further include a port providing flow through fluid communicationwith the sample cuvette 114.

The sample cuvette 114 has a removable cuvette lid 116 that need not betransparent. The cuvette lid 116 is desirably made of, or includes amaterial such as rubber, silicone, or another similar elastic material.The cuvette lid 116 can thus be capable of forming a seal against thesample cuvette 114 to prevent leakage of the fluid sample.

The cap 102 c can also include an access panel such as a hinged lid 117that opens to allow access for an operator to load the sample cuvette114 into the sample chamber 102 b. Alternatively, the access panel couldtake the form of a sliding cover, a fully removable cover, or any numberof other lid designs.

The exemplary hinged lid 117 is shown in FIG. 1 in an open position, andin FIG. 2 in a closed position. The hinged lid 117 can include astabilizing feature 118 that helps to hold the sample cuvette 114 in afixed position. The hinged lid 117 can further include a latch 120 thatholds the hinged lid 117 securely closed during a sample analysis run.The securing engagement may be selectively releasable under a moderateapplication of pulling force or tension on the hinged lid 117.Additionally or alternatively, the hinged lid 117 can be released by anoperator action such as, for example, pressing one or both of thefunction buttons 110.

As shown in FIG. 2, a finger indentation 200 can be provided in the topsurface of the hinged lid 117 to facilitate selective opening and/orsecure closure by applying pressure directly over the latch 120. Thehinged lid 117 can be coupled to the sample cuvette 114 such that whenthe hinged lid 117 is closed, the sample cuvette 114 is held down in afixed position within the sample chamber 102 b. When the hinged lid 117is in an open position, the sample cuvette 114 can be automaticallyreleased by a biasing member (e.g., spring) so that the sample cuvette114 pops up out of the sample chamber 102 b for ease of removal. WhileFIGS. 1 and 2 indicate certain shapes and/or dimensions (e.g., acylindrical housing) which may be suitable for some embodiments, thesampling device 100 may employ other shapes and/or dimensions. Thus, thespecified shapes and/or dimensions should not be considered limiting.FIG. 3 presents a view 300 of the housing cap 102 c, showing a pair ofhinges 302 about which the hinged lid 117 pivots. In one embodiment, thehinges 302 are located near the perimeter of the cap 102 c. It is notedthat any number of alternative lid configurations can be substituted forthe hinged lid 117 shown.

FIG. 4 depicts a view 400 of the housing 102, showing a plurality offeet 402 a, 402 b, 402 c, and 402 d, (four shown, collectively 402) onwhich the sampling device 100 can rest on a table top or desk top, forexample. Also shown in FIG. 4 is a pair of screws 404 a and 404 b (twoshown, collectively 404) and a drain hole 406. The drain hole 406 canprevent any liquid that may escape both the sample cuvette 114 and thesample chamber 102 b from accumulating inside the housing 102.

FIG. 5 shows a view 500 of the back of the sampling device 100, in whichis shown a panel 502 surrounding a cable receptacle 504. The panel 502may be a removable access panel. While the cable receptacle 504 ispictured as a USB port it is not so limited. One or more other types ofcommunications ports and/or power supply connections, or combinationsthereof, may be provided in conjunction with the panel 502. Suchconnections may provide pathways for power delivery and uni-directionalor bi-directional data flow to support the functions of the samplingdevice 100. Alternatively, or in addition, power and/or data connectionsto the sampling device 100 can be partly or fully wireless, therebyallowing data upload to a Web site via the Internet, for example.Instructions may also be received by the sampling device via the cablereceptacle 504 or via a wireless connection.

FIG. 6 shows a view 600 of internal parts within the sampling device 100relative to the sample cuvette 114. In the center is shown the topsurface of the cuvette lid 116. Inside the illustrated sampling device100 are shown four printed circuit board assemblies (PCBAs): atransducer PCBA 602, a calibrator PCBA 604, a direct sensor PCBA 606,and a backplane PCBA 608, which also serves as an indirect sensor PCBA.In the embodiment shown, the PCBAs 602, 604, and 606 are orientedsubstantially parallel to one another and substantially perpendicular tothe backplane PCBA 608, to which they connect. This orientation of thePCBAs provides a rigid structure that helps to direct theelectromagnetic energy path. As illustrated, the backplane PCBA 608 maybe sized and dimensioned to be securely received in housing 102, forexample engaging an inner periphery of the housing base 106 a, an innerperiphery of the side wall 108, or other attachment structures.Engagement may be via a press fit or via some coupling structure such asa detent structure, or a clip as shown below in FIG. 12 to secure thePCBAs 602, 604, and 606.

The PCBAs 602, 604, 606, and 608 may comprise any of a large variety ofmaterials, for example plastics metals, or composite materials. ThePCBAs are typically opaque or substantially opaque, at least toelectromagnetic energy that is employed in the analysis or evaluation ofthe samples or specimens. The PCBAs may, for example, be painted black,coated black, or may include black pigments.

According to one embodiment, the function buttons 110 and visualindicators 112 are shown mounted to the top of the transducer PCBA 602.The function buttons 110 are further shown attached to function buttonsupport plates 610 via function button fasteners 612. The functionbutton support plates 610 are coupled to the transducer PCBA 602 byfunction button coupling pins 614 that are through-hole mounted to thetransducer PCBA 602. Electrical connections from the function buttons110 are also coupled to internal electronic and/or electrical componentsvia the transducer PCBA 602. Similarly, the visual indicators 112 areattached to indicator support plates 616, and the indicator supportplates 616 are coupled to the transducer PCBA 602 via indicator couplingpins 618. Other form factors for the function buttons 110, visualindicators 112, and associated connections, or an alternative userinterface can be substituted for those shown.

As explained in more detail below, the transducer PCBA 602 includes aplurality of transducers, typically in the form of a plurality ofemitters (seven shown, collectively 634). The calibrator PCBA 604includes one or more calibration detectors or sensors (four shown,collectively 636). The direct sensor PCBA 606 includes one or more firstprimary sampling detectors or sensors (four shown, collectively 638).Also as explained in more detail below, the backplane PCBA 608 includesone or more second primary sampling detector(s) or sensor(s) (fourshown, collectively 640), and various other electrical and electroniccomponents (collectively 642) to control operation of the samplingdevice 100 and/or communications therefrom. The transducer PCBA 602, thecalibrator PCBA 604, and the direct sensor PCBA 606 each include arespective coupler or connector 644 a, 644 b, and 644 c, respectively,to communicatively couple electronic and/or electrical components orcircuits of the each of the PCBAs 602, 604, and 606 with the componentsor circuits of the backplane PCBA 608. Accordingly, the backplane PCBA608 can be configured with a plurality of sockets for receiving theconnectors 644 a, 644 b, and 644 c. Connectors 644 a, 644 b, and 644 cmay be slot connectors having a slot sized and dimensioned to mate witha coupler of the transducer PCBA 602, for instance an edge or tab. Eachof the couplers or connectors 644 a, 644 b, and 644 c typically carry avariety of electrical contacts, although other signal transferstructures (e.g., optical fiber) can be employed.

Power can also be supplied to each of the PCBAs 602, 604, and 606through the connectors 644 a, 644 b, and 644 c. A power source (notshown) may take the form of a portable power source, for example one ormore batteries, fuel cells, and/or super- or ultra-capacitors.Additionally, or alternatively, the power source may take the form of afixed power source, such as a cable plugged into a port of a computer(e.g., USB cable) or a conventional electrical receptacle (e.g., walloutlet).

The backplane PCBA 608 may, for example, optionally include a controlsubsystem 646 implemented as one or more integrated circuit chipsattached to the PCBA 608. Alternatively, the sampling device 100 may becoupled to an external control system, for example one or moreprogrammed general purpose or special purpose computers or computersystems.

The control subsystem 646 may, for example, be coupled to a centralcommunications port 647 (e.g., Universal Serial Bus (USB) or mini-USBcompliant female connector) as shown in FIG. 6. The centralcommunications port 647 may be accessible from the exterior of thehousing 102, for example via the cable receptacle 504 and the removableaccess panel 502 in the surface of the housing 102. While illustrated asa hardwired communication port 647 (e.g., a USB port), the samplingdevice 100 may include other types of communications ports or devices,for instance an infrared transceiver, or an RF transceiver (e.g.,BLUETOOTH® transceiver). Such may allow the transmission of data,instructions and/or results, to or from the sampling device 100.

The control subsystem 646 may also include one or more controllers 648,for example, one or more microprocessors, digital signal processors(DSPs), application specific integrated circuits (ASICs), programmablegate arrays (PGA), programmable logic controllers (PLCs), or other logicexecuting device. The control subsystem may include one or morenon-transitory computer- or processor-readable media, for example one ormore memories 650 such as read only memory (ROM) 650 a, or Flash memory650 b and random access memory (RAM) 650 c. One or more buses (notshown) may couple the ROM 650 a and RAM 650 c to the controller 648. Thebuses may take a variety of forms including an instruction bus, databus, other communications bus and/or power bus. A nonvolatile ROM and/orFlash memory 650 b may store instructions and/or data for controllingthe sampling device 100. The volatile RAM 650 c may store instructionsand/or data for use during operation of the sampling device 100.

The optional controller 648 can employ instructions and or data from theROM/Flash 650 b and RAM 650 c in controlling operation of the samplingdevice 100. For example, the controller 648 operates the emitters 634 inone or more sequences. The sequences determine an order in which theemitters 634 are turned ON and OFF. The sequences may also indicate anordered pattern of drive levels (e.g., current levels, voltage levels,duty cycles) for the emitters 634. Thus, for example, a controller 648may cause the application of different drive levels to respective onesof the emitters 634 to cause the emitters 634 to emit in distinct bandsof the electromagnetic spectrum. Thus, the ranges of wavelengths of someof the emitters can be different from the ranges of wavelengths ofothers of the emitters.

The controller 648 may process information generated by the primarysampling detector(s) or sensor(s) 638, 640, which is indicative of theresponse by at least a portion of a sample or specimen to illuminationby the emitters 634. The information at any given time may be indicativeof the response by the sample or specimen to illumination by one or moreof the emitters 634. Thus, the information over a period of time may beindicative of the responses by the sample or specimen to sequentialillumination by each of a plurality of the emitters 634, where each ofthe emission spectra of each of the emitters 634 has a different center,bandwidth and/or other more complex differences in spectral content,such as those described above (e.g., width of the band, the skew of thedistribution, the kurtosis, etc.). The control subsystem 646 mayoptionally include a buffer (not shown) to buffer information receivedfrom the primary sampling detector(s) or sensor(s). The controlsubsystem 646 may further optionally include an analog to digitalconverter (ADC) (not shown) and/or digital to analog converter (DAC)(not shown). An ADC may, for example, be used for converting analogphotodiode responses into digital data for further analysis and/ortransmission. A DAC may, for example, be used for converting digitalcomputer or controller commands into analog LED current levels. Thecontrol subsystem may additionally or alternatively optionally includean analog signal processor, which may be particularly useful where thesensor takes the form of one or more photodiodes.

The control subsystem 646 may include a user interface including one ormore user interface devices. For example, the control subsystem 646 mayinclude one or more speakers or microphones (not shown). Also forexample, the control subsystem 646 may include and/or one or more visualindicators, such as one or more LEDs, liquid crystal displays (LCD), orother visual indicators, which could include visual indicators 112. TheLCD may, for example, take the form of a touch sensitive LCD, whichdisplays a graphical user interface, operable by the user of thesampling device 100.

Additionally, or alternatively, the control subsystem 646 may includeone or more user operable input elements, such as switches, keys orbuttons, which may include the function buttons 110. The input elementsmay include a switch for turning the sampling device 1000N and OFF.Additionally, or alternatively, the input elements may include one ormore switches or keys for controlling operation of a test device thatcan, for example, download or upload data or instructions to, or fromthe sampling device 100.

FIG. 7 shows a view 700 of the interior parts shown in FIG. 6, relativeto the cap 102 c and to the sample chamber 102 b. FIG. 7 also shows,from above the sampling device 100, the system geometry, includinglocations of the emitters 634 and the primary sampling detectors orsensors 638 and 640.

FIG. 7 further includes a ray drawing superimposed onto the view 700, inwhich arrows indicate transmission paths of electromagnetic energyrelative to the interior parts of the sampling device 100. In oneembodiment, emitters 634 are selectively operable to emitelectromagnetic energy in a respective range of wavelengths through anemission angle that is substantially centered on an optical axis 702.The electromagnetic energy is generally blocked by the calibrator PCBA604 except where the energy is transmitted through a PCBA slit 704 inthe calibrator PCBA 604. The PCBA slit 704 can be substantially alignedwith one or more of the emitters 634. Electromagnetic waves admittedthrough the PCBA slit 704 continue to propagate toward and through afirst aperture 706 of the sample chamber 102 b and through thetransparent walls of the sample cuvette 114. A second aperture 708 ofthe sample chamber 102 b is positioned at least partially across atleast a portion of the sample chamber 102 b from the first aperture 706.A third aperture 710 of the sample chamber 102 b is positioned at leastpartially across at least a portion of the sample chamber 102 b fromboth the first and the second apertures 706 and 708, respectively. Thefirst, second, and third apertures, 706, 708, and 710 are transmissiveof electromagnetic energy of at least some wavelengths in an opticalportion of the electromagnetic spectrum, as is the sample cuvette 114.

As the ray drawing indicates, electromagnetic energy strikes the sampleor specimen and is scattered and/or reflected therefrom. The scatteredelectromagnetic waves then emerge from the at least partiallytransparent walls of the sample cuvette 114, propagating outward invarious directions. Again, the electromagnetic energy is generallyblocked by the walls of the sample chamber 102 b, except where thesecond aperture 708 permits transmission in the forward scatteringdirection, along the optical axis 702. The third aperture 710 permitstransmission of the scattered energy in a direction perpendicular to theoptical axis 702, along a perpendicular axis 703.

After passing through the second aperture 708, a portion of scatteredelectromagnetic energy propagating along the optical axis 702 fallsincident on, and thus can be detected by the first primary samplingdetector(s) or sensor(s) 638 mounted on the direct sensor PCBA 606.Similarly, after passing through the third aperture 710, a portion ofscattered electromagnetic energy propagating along the perpendicularaxis 703 can be detected at one or more of the second primary samplingdetector(s) or sensor(s) 640 mounted on the direct sensor PCBA (also thebackplane PCBA) 608. In some applications, time varying processes, forexample, chemical or biological reactions, can be monitored by detectingthe onset of, or change(s) in, “side scatter” along the perpendicularaxis 703. Onset of such side scatter can indicate, for example,formation of crystals, bacterial growth, formation of blood clots, orother substances in a fluid that can cause electromagnetic energy to bescattered in the direction of the second primary sampling detector(s) orsensor(s) 640. Commensurate with an increase in side scatter along theperpendicular axis 703, there may be observed a decrease in transmissionof electromagnetic energy along the optical axis 702. In some instances,such a decrease in transmission intensity and an increase in sidescatter intensity can be observed substantially simultaneously (i.e.,concurrently) using the sampling device 100. The ability to detect suchchanges represents a feature of the sampling device 100 that is notprovided by other types of sampling devices.

FIG. 8 shows a view 800 of the sample chamber 102 b. The sample chamber102 b receives and protects the sample cuvette 114 containing the fluidsample under test. The sample cuvette 114 can be inserted at leastpartially into the center of the sample chamber 102 b, which fitsclosely around the sample cuvette 114. In one embodiment, the samplechamber 102 b can be raised and lowered during loading of the samplecuvette. The sample chamber 102 b can serve as a double containmentreceptacle to prevent liquids that may escape the sample cuvette 114from coming into contact with electronic components of the samplingdevice 100. The sample chamber 102 b can feature a plurality ofapertures described above, e.g., the first aperture 706, the secondaperture 708, and the third aperture 710, to allow electromagneticenergy to be transmitted to and scattered (or re-emitted) from a samplewithin the sample cuvette 114. In this way, the sample chamber 102 bguides light into the sample cuvette 114. Otherwise, the walls of thesample chamber can be opaque, such that the sample chamber 102 b has atleast one opaque wall. The first aperture 706 in the sample chamber 102b allows passage of incident electromagnetic energy from one or more ofthe emitters 634, along the optical axis 702, and through the samplecuvette 114 to interact with the fluid sample. In one embodiment, thesecond aperture 708 is diametrically opposed to the first aperture 706,allowing passage of scattered electromagnetic energy in the forwarddirection to exit the sample chamber 102 b for detection. The thirdaperture 710 is disposed along a second axis 703, non-collinear with theoptical axis 702. In the embodiment shown, the second axis 703 and thethird aperture 710 are oriented perpendicular to the optical axis 702.As illustrated, the first aperture 706 is shown larger than the thirdaperture 710. However, the relative dimensions of the apertures 706,708, and 710 can change depending on the type of emitters 634, thenature of the sample, and other variables.

FIG. 9 shows a view 900 of the PCBAs 602, 604, 606, and 608, relative tothe sample cuvette 114, in which the calibration sensors 636 and theprimary sampling detector(s) or sensor(s) 638, 640 are visible. In anexemplary embodiment, the PCBAs 602, 604, 606, and 608 can attach to thehousing 102 by fitting notches 902 onto clips 904 (see FIG. 12). Theclips 904 can, in turn, be secured to an interior surface of the base ofthe housing 106 a. When mounted in front of the transducer PCBA 602, thecalibrator PCBA 604 serves as a mask in which the PCBA slit 704 allowselectromagnetic energy to reach and interact with the fluid sample. Thetransparent sample cuvette 114 allows electromagnetic energy scatteredfrom the fluid sample to reach the primary sampling detector(s) orsensor(s) 638.

As is best illustrated in FIG. 9, the transducer PCBA 602 carries anumber of emitters or sources 634 arranged, for example, in a lineararray on the transducer PCBA 602. The emitters 634 may be all alignedwith the PCBA slit 704 and the first aperture 706. A full range ofemitters can include, for example, 5-10 emitter chips in which eachemitter can be made to produce a range of wavelengths of light dependingon the electric current supplied to it. Respective ranges of emitterscan overlap such that a full range of desired wavelengths can beproduced by driving a few emitters at many different current levels. Theemitters 634 may take a variety of forms which are operable to emitelectromagnetic energy. The emitters 634 may, for example, take the formof one or more light emitting diodes (LEDs), including for instanceorganic LEDs (OLEDs). Alternatively, or additionally, the emitters 634may take the form of one or more lasers, for example one or more laserdiodes. The lasers may, or may not, be tunable lasers. Alternatively, oradditionally, the emitters 634 may take the form of one or moreincandescent sources such as conventional or halogen light bulbs.

One, more, or all of the emitters 634 may be operable to emit in part orall of an “optical” portion of the electromagnetic spectrum, includingthe (human) visible portion, near infrared (N-IR) portion and/or or nearultraviolet (N-UV) portions of the electromagnetic spectrum.Additionally, or alternatively, the emitters 634 may be operable to emitelectromagnetic energy other portions of the electromagnetic spectrum,for example the infrared, ultraviolet and/or microwave portions.

In some embodiments, at least some of the emitters 634 are operable toemit in or at a different band than other of the emitters 634. Forexample, one or more emitters 634 may emit in a band centered around 450nm, while one or more of the emitters 634 may emit in a band centeredaround 500 nm, while a further emitter or emitters emit in a bandcentered around 550 nm. Each of the emitters 634 may emit in a bandcentered around a respective frequency or wavelength, different thaneach of the other emitters 634. Using emitters 634 with different bandcenters advantageously maximizes the number of distinct samples that maybe captured from a fixed number of emitters 634. This may beparticularly advantageous where the sampling device 100 is relativelysmall, and has limited space or footprint for the emitters 634.

The distribution of spectral content for each emitter 634 may vary as afunction of drive level (e.g., current, voltage, duty cycle),temperature, and other environmental factors, depending on the specificemitter 634. Such variation may be advantageously actively employed tooperate one or more of the physical emitters 634 as a plurality of“logical emitters or sources,” each of the logical emitters or sourcesoperable to provide a respective emission spectra from a respectivephysical emitters or source 634. Thus, for example, the center of theband of emission for each emitters or source 634 may vary according to adrive level and/or temperature. For example, the center of the band ofemission for LEDs will vary with drive current or temperature. One waythe spectral content can vary is that the peak wavelength can shift.However, the width of the band, the skew of the distribution, thekurtosis, etc., can also vary. Such variations may be also beadvantageously employed to operate the physical emitters or sources 634as a plurality of logical emitters or sources. Thus, even if the peakwavelength were to remain constant, the changes in bandwidth, skew,kurtosis, and any other change in the spectrum can provide usefulvariations in the operation of the sampling device 100. Likewise, thecenter of the band of emission may be varied for tunable lasers. Varyingthe center of emission bands for one or more emitters 634 advantageouslymaximizes the number of samples that may be captured from a fixed numberof emitters 634. Again, this may be particularly advantageous where thesampling device 100 is relatively small, and has limited space orfootprint for the emitters 634.

As is best illustrated in FIG. 10, the calibration PCBA 604 carries anumber of calibration detectors or sensors (four shown, collectively636), arranged around the PCBA slit 704. The number of calibrationdetectors or sensors 636 can correspond to the number of emitters 634.The calibration detectors or sensors 636 are generally aligned withrespective emitters 634, the calibration detectors or sensors 636 andemitters 634 for example being arranged in linear segments on a surfaceof the calibration PCBA 604. The calibration detectors or sensors 636may match a nominal output of the respective emitter 634 to which thecalibration detector or sensor 636 is paired. Thus, some of thecalibration detectors or sensors 636 may be responsive to differentrespective bands of wavelengths than the others. Such bands may bemutually exclusive or may be overlapping. Some embodiments employ one ormore wideband calibration detectors or sensors 636, for example, apyroelectric detector from Pyreos Ltd. Such may advantageously reduceparts counts, while still allowing calibration across the range ofwavelengths of the emitters 634. Optionally, one or more filters (notshown) may be employed with the calibration detectors or sensors 636,for example one or more low pass filters, high pass filters, and/or bandpass filters. The filters may be optical filters and may be formed orcarried directly on the calibration detectors or sensors 636.Alternatively, the filters may be formed on or carried on anothersurface, in the field of view of but spaced from the calibrationdetectors or sensors 636.

The calibration detector(s) or sensor(s) 636 can take a variety of formssuitable for sensing or responding to electromagnetic energy. Forexample, the calibration detector(s) or sensor(s) 636 may take the formof one or more photodiodes (e.g., germanium photodiodes, siliconphotodiodes). Alternatively, or additionally, the calibrationdetector(s) or sensor(s) 636 may take the form of one or morephotomultiplier tubes. Alternatively, or additionally, the calibrationdetector(s) or sensor(s) 636 may take the form of one or more CMOS imagesensors. Alternatively, or additionally, the calibration detector(s) orsensor(s) 636 may take the form of one or more charge coupled devices(CCDs). Alternatively, or additionally the calibration detector(s) orsensor(s) 636 may take the form of one or more micro-channel plates.Other forms of electromagnetic sensors may be employed, which aresuitable to detect the wavelengths expected to be returned in responseto the particular illumination and properties of the object beingilluminated.

The calibration detector(s) or sensor(s) 636 may be formed as individualelements, one-dimensional array of elements and/or two-dimensional arrayof elements. For example, the calibration detector(s) or sensor(s) 636may be formed by one germanium photodiode and one silicon photodiode,each having differing spectral sensitivities. A test device may employ anumber of photodiodes with identical spectral sensitivities, withdifferent colored filters (e.g., gel filters, dichroic filters,thin-film filters, etc) over the photodiodes to change their spectralsensitivity. This may provide a simple, low-cost approach for creating aset of sensors with different spectral sensitivities, particularly sincegermanium photodiodes are currently significantly more expensive thatsilicon photodiodes. Also for example, the calibration detector(s) orsensor(s) 636 may be formed from one CCD array (one-dimensional ortwo-dimensional) and one or more photodiodes (e.g., germaniumphotodiodes and/or silicon photodiodes). For example, the calibrationdetector(s) or sensor(s) 636 may be formed as a one- or two-dimensionalarray of photodiodes. A two-dimensional array of photodiodes enablesvery fast capture rate (i.e., camera speed) and may be particularlysuited to use in assembly lines or high speed sorting operations. Forexample, the calibration detector(s) or sensor(s) 636 may be formed as aone- or two-dimensional array of photomultipliers. Combinations of theabove elements may also be employed.

In some embodiments, the calibration detector(s) or sensor(s) 636 may bea broadband sensor sensitive or responsive over a broad band ofwavelengths of electromagnetic energy. In some embodiments, thecalibration detector(s) or sensor(s) 636 may be narrowband sensorssensitive or responsive over a narrow band of wavelengths ofelectromagnetic energy. In some embodiments, the calibration detector(s)or sensor(s) 636 may take the form of several sensor elements, as leastsome of the sensor elements sensitive or responsive to one narrow bandof wavelengths, while other sensor elements are sensitive or responsiveto a different narrow band of wavelengths. This approach mayadvantageously increase the number of samples that may be acquired usinga fixed number of sources. In such embodiments the narrow bands may, ormay not, overlap.

As is best illustrated in FIG. 11, the direct sensor PCBA 606 carries anumber of first primary sampling sensors 638 a-638 d (four shown,collectively 638) positioned opposite the PCBA slit 704. The firstprimary sampling sensors 638 may, for example, include two or moresampling sensors or detectors, each responsive to a respective band ofwavelengths. Such bands may be mutually exclusive or overlapping. Theillustrated embodiment employs four first primary sampling detectors orsensors 638 a-638 d, each responsive to a respective band of wavelengths(i.e., 400 nm-1100 nm, 400 nm-1050 nm, 400 nm-1050 nm, 600 nm-1700 nm,respectively). Three of the first primary sampling detectors or sensors638 a-638 c that are responsive to N-UV wavelengths are employed toincrease to sensitivity. Another embodiment employs one or more widebandfirst primary sampling detector(s) or sensor(s) 638 d, for example, apyroelectric detector from Pyreos Ltd. Optionally, one or more filters(not shown) may be employed with the first primary sampling detector(s)or sensor(s) 638, for example one or more low pass filters, high passfilters, and/or band pass filters. The filters may be optical filtersand may be formed or carried directly on the first primary samplingdetector(s) or sensor(s). Alternatively, the filters may be formed on orcarried on another surface, in the field of view of but spaced from thefirst primary sampling sampling detector(s) or sensor(s) 638.

The first primary sampling detector(s) or sensor(s) 638, orspectrophotometers, can take a variety of forms suitable for sensing orresponding to electromagnetic energy. For example, the primary samplingsensor(s) 638 may take the form of one or more photodiodes (e.g.,germanium photodiodes, silicon photodiodes). Alternatively, oradditionally, the primary sampling detector(s) or sensor(s) 638 may takethe form of one or more photomultiplier tubes. Alternatively, oradditionally, the first primary sampling detector(s) or sensor(s) 638may take the form of one or more CMOS image sensors. Alternatively, oradditionally, the first primary sampling detector(s) or sensor(s) 638may take the form of one or more charge coupled devices (CCDs).Alternatively, or additionally the first primary sampling detector(s) orsensor(s) 638 may take the form of one or more micro-channel plates.Other forms of electromagnetic sensors may be employed, which aresuitable to detect the wavelengths expected to be returned in responseto the particular illumination and properties of the object beingilluminated.

The first primary sampling detector(s) or sensor(s) 638 may be formed asindividual elements, one-dimensional array of elements and/ortwo-dimensional array of elements. For example, the first primarysampling detector(s) or sensor(s) 638 may be formed by one germaniumphotodiode and one silicon photodiode, each having differing spectralsensitivities. A test device can be configured with a number ofphotodiodes having identical spectral sensitivities, with differentcolored filters (e.g., gel filters, dichroic filters, thin-film filters,etc.) over the photodiodes to change their spectral sensitivity. Thismay provide a simple, low-cost approach for creating a set of sensorswith different spectral sensitivities, particularly since germaniumphotodiodes are currently significantly more expensive that siliconphotodiodes. Also for example, the first primary sampling detector(s) orsensor(s) 638 may be formed from one CCD array (one-dimensional ortwo-dimensional) and one or more photodiodes (e.g., germaniumphotodiodes and/or silicon photodiodes). For example, the first primarysampling detector(s) or sensor(s) 638 may be formed as a one- ortwo-dimensional array of photodiodes. A two-dimensional array ofphotodiodes enables very fast capture rate (i.e., camera speed) and maybe particularly suited to use in assembly lines or high speed sortingoperations. For example, the first primary sampling detector(s) orsensor(s) 638 may be formed as a one- or two-dimensional array ofphotomultipliers. Combinations of the above elements may also beemployed.

In some embodiments, the primary sampling detector(s) or sensor(s) 638,640 may be a broadband sensor sensitive or responsive over a broad bandof wavelengths of electromagnetic energy. In some embodiments, theprimary sampling detector(s) or sensor(s) 638, 640 may be narrowbandsensors sensitive or responsive over a narrow band of wavelengths ofelectromagnetic energy. In some embodiments, the primary samplingdetector(s) or sensor(s) 638, 640 may take the form of several sensorelements, as least some of the sensor elements sensitive or responsiveto one narrow band of wavelengths, while other sensor elements aresensitive or responsive to a different narrow band of wavelengths. Thisapproach may advantageously increase the number of samples that may beacquired using a fixed number of sources. In such embodiments the narrowbands may, or may not, overlap.

At least one of the PCBAs 602, 604, 606, and 608 can also carry one ormore thermal sensors (not explicitly shown). The thermal sensors aredesirably distributed to detect temperature at a variety of points orlocations. Such temperatures may be indicative of temperatures to whichthe emitters 634, first primary sampling detectors or sensors 638 and/orcalibration detectors or sensors 636 are subjected. Temperatureindicative signals from the thermal sensors may be employed incalibration, for example, calibrating results or responses and/orcalibrating drive signals to account from variation from nominaltemperatures or other conditions.

Table A, below, provides an exemplary list of suitable parts for theemitters and sensors. Such is purely illustrative and is not intended torequire any specific parts, specific wavelengths, or sensitivities.

TABLE A Ref. No. Part No. Description Default/Qty. 606 Max2 Sensor PCBAPCBA 1 — MCP98242 Thermal Sensor 4 644a HSEC8-120-01-X-DV Connector 1634a 350-PLCC2-120 352 nm 1 634b SM1206UV-395-IL 400 nm 1 634cEL-19-21/BHC-AN1P2/3T 468 nm 1 634d PG1112C-TR 567 nm 1 634eLTST-C190KYKT 595 nm 1 634f SMC810 810 nm 1 634g SMC1200 1200 nm 1 634hLNJ812R83RA 630 nm 1 634i SMC1450 1450 nm 1 634j SMC910 910 nm 1 634kLN1251CTR 700 nm 1 634l SMC970 970 nm 1 636a PDB-C152SM 400-1100 nm 1636b SFH2701 400-1050 nm 1 636c PDB-C152SM 400-1100 nm 1 636dLAPD-1-06-17-LCC 600-1700 nm 1 638a SFH2701 400-1050 nm 1 638b SFH2701400-1050 nm 1 638c PDB-C152SM 400-1100 nm 1 638d PDB-C152SM 400-1100 nm1 638e PDB-C152SM 400-1100 nm 1 638f PDB-C152SM 400-1100 nm 1 638gLAPD-1-06-17-LCC 600-1700 nm 1 638h PDB-C152SM 400-1100 nm 1 638iLAPD-1-06-17-LCC 600-1700 nm 1 638j PDB-C152SM 400-1100 nm 1 638kPDB-C152SM 400-1100 nm 1 638l PDB-C152SM 400-1100 nm 1

By commonly housing emitters 634 with respective calibration detector(s)or sensor(s) 636 or sensors 638, the sampling device may automaticallytake or capture an electromagnetic energy calibration sample ormeasurement each time an emitter emits electromagnetic energy. Such isperformed in real-time, without any separate calibration mode. Such maybe performed individually for each emitter, one at a time, as theemitter is activated. Thermal sensors 635 may be sampled each time anemitter is activated. Alternatively, the thermal sensors 635 may besampled periodically or aperiodically. The electromagnetic energycalibration sample or measurements and thermal calibration sample ormeasurements may be used to calibrate a detected or measured response.The electromagnetic energy calibration sample or measurements andthermal calibration sample or measurements may additionally oralternatively be used to control operation, for instance to control adrive signal supplied to the emitters, or control an amplificationapplied to a signal produced or provided by the first primary samplingdetectors or sensors 638. As discussed below, the electromagnetic energycalibration sample or measurements and thermal calibration sample ormeasurements may be processed on the sampling device 100, or sent to aseparate component (e.g., digital computer) for processing.

While FIGS. 9-11 show seven emitters 634, four calibration detector(s)or sensor(s) 636 and eight primary sampling detectors or sensors 638,640, other embodiments may include fewer or greater number of emitters634, and calibration detector(s) or sensor(s) 636 or primary samplingdetector(s) or sensor(s) 638, 640. The total number of emitters 634,calibration detector(s) or sensor(s) 636, and primary samplingdetector(s) or sensor(s) 638, 640, should not be considered limiting.

FIG. 12 shows a view 1200 of the sampling device 100 as seen from therear. Internal parts are shown relative to overall structural componentssuch as the main body housing portion 102 a, the cap 102 c, the hingedlid 117, and the sample chamber 102 b. Superimposed onto the structureof the sampling device 100 is a side view of a ray diagram similar tothat shown in FIG. 7. In the view 1200, electromagnetic energy is shownbeing emitted through a wide range of angles from the exemplary top andbottom emitters 634 a and 634 g. The diameter of the emitted beam maydepend on the nature of the emitter. The outermost rays 1202 a and 1202g, emanating from the emitters 634 a and 634 g, respectively, fail topass through the PCBA slit 704 (not shown) and therefore do not interactwith the sample. If the emitters 634 are laser sources, for example, theoutermost rays may not be relevant because laser sources produce acollimated beam. (However, even a collimated beam may exhibitspreading.) In general, a portion of the energy emitted can be expectedto escape the system without encountering the sample under test. Theinnermost rays emitted, 1204 a and 1204 g, respectively, are showncrossing at the center of the sample cuvette 114, in front of the secondprimary sampling detector(s) or sensor(s) 640, which are attached to thebackplane 608. The innermost rays therefore interact with substantiallythe same part of the sample contained in the sample cuvette 114. It isnoted that the innermost rays shown have different wavelengths becausethey originate at different sources. A portion of the electromagneticenergy in the innermost rays 1204 a and 1204 g is scattered by thesample. Some of the scattered energy is shown continuing to propagate inthe forward direction for detection by the sensors 638. Thus, comparingthe energy scattered by the same sample at multiple wavelengths permitsidentification of a localized portion of the sample. Meanwhile, thecentral rays 1206 a and 1206 g, from the two different emitters 634 aand 634 g, respectively, interact with different portions of the fluidsample. The central rays are also scattered, and a portion of thisscattered energy propagates to the detectors 638. By comparing thescattered energy from the central rays 1206 a and 1206 g with that fromthe innermost rays 1204 a and 1204 g, information about the homogeneityof the sample can be obtained. For example, particles suspended in thefluid can be identified and distinguished from the fluid itself.

FIG. 13 shows a sampling system 1300, according to one illustratedembodiment. The sampling system 1300 includes one or more samplingdevices 100 (one shown). The sampling system 1300 includes one or moreprocessor-based devices 1302 (one shown). While illustrated as a mobileor handheld processor-based device 1302, for instance a Smartphone typedevice, the processor-based device 1302 may take a large variety ofother forms. For example, the mobile or handheld processor-based device1302 may take the form of the various computers or computing systems,such as a desktop or laptop personal computer, tablet computer, netbookcomputer, mini-computer, mainframe computer, or server computer.

The sampling device 100 is communicatively coupled to theprocessor-based device 1302.

The sampling device 100 may be communicatively coupled to theprocessor-based device 1302 via a physical communicative path such as acable 1304.

The cable 1304 will typically include a connector proximate at least oneend thereof, and often at both ends. For example, the cable 1304 mayhave a first connector 1304 a (e.g., plug) at a first end 1306 a, thefirst connector 1304 a selectively detachably coupleable to acomplimentary connector or port 1308 on the processor-based device 1302.Also for example, the cable 1304 may have a second connector 1304 b(e.g., plug) at a second end 1306 b, the second connector 1304 bselectively detachably coupleable to a complimentary connector or porton the sampling device 100 such as the cable receptacle 504.Alternatively, the second end of the cable 1304 may be permanently fixedto the sampling device 100. The physical ports and/or connectors 1304 a,1304 b, 1308, 504 and/or cables 1304 may comply with any variety ofphysical and/or logical standards, and may incorporate one or moreintegrated circuits. For instance, the ports and/or connectors 1304 a,1304 b, 1308, 504 and/or cables 1304 may comply with standards requiredof USB® standards or Apple Computer's Lighting® standards.

The cable 1304 may, for instance, include a number of distinctelectrical conductors (e.g., wires) (not shown) to provide signalsbetween the sampling device 100 from the processor-based device 1302.The electrical conductors may provide for bi-directional communicationsbetween the sampling device 100 and the processor-based device 1302. Thecable 1304 may additionally provide electrical power (e.g., 5V, 10V) tothe sampling device 100 from the processor-based device 1302. In such animplementation, the sampling device 100 may omit any on-board consumablepower source (e.g., primary or secondary chemical battery,ultra-capacitor, fuel cell) (not shown). Alternatively, the samplingdevice 100 may include a recharging circuit (not shown) that useselectrical power supplied via the cable 1304 to recharge an onboardpower source (e.g., secondary chemical battery, ultra-capacitor, fuelcell) (not shown).

The cable 1304 may include one or more optical paths (e.g., opticalfibers) (not shown). The optical paths may provide for bi-directionalcommunications between the sampling device 100 and the processor-baseddevice 1302.

The sampling device 100 may be communicatively coupled to theprocessor-based device 1302 via a wireless (e.g., radio frequency,microwave, visible or IR light) communicative path. As discussed below,many processor-based devices 1302 include various radios or receivers,including ones that are compliant with cellular (e.g., CDMA, GSM, LTE),BLUETOOTH or WI-FI protocols. In such implementations, the samplingdevice 100 may include one or more radios or transceivers (not shown)can be implemented as one or more integrated circuits and/or antennas(not shown). The integrated circuits and/or antennas (not shown) may becarried by the backplane PCBA 608 or some other PCBA, for instance adedicated communications PCBA (not shown). In such implementations, thesampling device 100 will typically require an on-board consumable powersource (e.g., primary or secondary chemical battery, ultra-capacitor,fuel cell) (not shown).

The sampling device 100 may be communicatively coupled via one or morenetworks (not shown) to various processor-based devices 1302 and/orother sampling devices 100. The network(s) may take a variety of formsincluding LANs, WANs, WLANs, WWANs, PSTN, to name a few. Such may, forexample allow access to one or more storage or databases of information.Such may, for example allow updating or reconfiguration, for instance bydownloading of processor-executable instructions. Such may, for example,allow troubleshooting of the sampling device 100 should an errorcondition occur.

The processor-based device 1302 may include a user interface which may,for example include a touch-sensitive display 1312, speakers 1314 (oneshown), microphones 1316 a, 1316 b (collectively 1316), and/or an audiooutput port 1318. The user interface may also include user selectableicons, collectively 1320, and/or one or more physical switches, keys orbuttons 1322.

FIG. 13 further illustrates a PCBA 1324 of the processor-based device1302, removed therefrom to better illustrate various components housedwithin a housing of the processor-based device 1302. The processor-baseddevice 1302 includes one or more processors, for instance amicroprocessor 1326. The processor-based device 1302 includes one ormore non-transitory computer- or processor-readable media, for instanceROM or Flash 1328 and/or RAM 1330.

Referring to FIG. 13, the microprocessor 1326 employs instructions andor data from the ROM/Flash 1328 and/or RAM 1330 in controlling operationof the sampling device 100. For example, the processor 1326 operates theemitters 634 in one or more sequences. The sequences determine an orderin which the emitters 634 are turned ON and OFF. The sequences may alsoindicate an ordered pattern of drive levels (e.g., current levels,voltage levels, duty cycles) for the emitters 634. Thus, for example,the processor 1326 may cause the application of different drive levelsto respective ones of the emitters 634 to cause the emitters 634 to emitin distinct bands of the electromagnetic spectrum. The processor 1326may process information generated by the first primary samplingdetector(s) or sensor(s) 638, which is indicative of the response by atleast a portion of a sample or specimen to illumination by the emitters634. The information at any given time may be indicative of the responseby the sample or specimen to illumination by one or more of the emitters634. Thus, the information over a period of time may be indicative ofthe responses by the sample or specimen to sequential illumination byeach of a plurality of the emitters 634, where each of the emissionspectra of each of the emitters 634 has a different center, bandwidthand/or other more complex differences in spectral content, such as thosedescribed above (e.g., width of the band, the skew of the distribution,the kurtosis, etc.).

The processor 1326 employs instructions and or data from the ROM/Flash1328 and RAM 1330 to perform analysis or evaluation of the responses.For example, the processor 1326 may compare a response to one or morereference responses. The processor 1326 may determine whether a responsefrom a sample or specimen sufficiently matches is signature responsesfrom a reference sample or specimen. Such may, for example, be employedto detect a presence or absence of a substance, for instance an illegalsubstance (e.g., cocaine), an explosive substance (e.g., nitrate based),or a toxic substance (e.g., carcinogens). The processor 1326 may causedisplay of a result of an analysis or evaluation. For instance, theprocessor 1326 may cause display of a simple indicator (e.g., check,YES/NO, other text, GREEN/RED/AMBER or other color) indicative of theresult. Also for instance, the processor 1326 may cause display of amore complex indicator (e.g., graph, table chart) indicative of theresult. Additionally or alternatively, the processor 1326 may cause anaural indication indicative of a result via speaker 1314, for example asound such as a beep, buzz, or even spoken or synthesized words.

The processor-based device 1302 may additionally include a displaydriver 1332, communicatively coupled to drive the touch-sensitivedisplay 1312 and/or detect touches, swipes or other user inputs via thetouch-sensitive display 1312. The display driver 1332 may be a dedicatedintegrated circuit, for example a graphical processing unit.

The processor-based device 1302 may additionally include one or moreradios or transceivers 1334 (only one shown) and one or more associatedantennas 1336 (only one shown). The radios or transceivers 1334 andantennas 1336 may take any of a large variety of forms, for example onessuitable for wireless communications such as cellular communications(e.g., CDMA, GSM, LTE), BLUETOOTH communications and/or WI-FIcommunications.

The processor-based device 1302 may additionally include one or moreaccelerometers or gyroscopes. Such components may be capable ofproducing data indicative of an orientation of the processor-baseddevice 1302. Such components may be capable of producing data indicativeof a speed, movement or acceleration of the processor-based device 1302.

The various components may be communicatively coupled via one or morebuses 1338 (only one shown) or other connections, for example databuses, instruction buses, address buses, power buses, etc.

As used herein and in the claims, longitudinal refers to the majordimension or length of a structure, and is not limited to being an axisof revolution of a profile or cross-section of such structure.

As used herein and in the claims, the term “non-transitorycomputer-readable medium” and “non-transitory processor-readable medium”are used interchangeably to refer to any tangible medium thatparticipates in providing instructions for execution or storage of data,parameters or other information. Such a medium may take many forms,including but not limited to, non-volatile media and volatile media.Non-volatile media includes, for example, hard, optical or magneticdisks. Volatile media includes dynamic memory, such as system memory.Common forms of computer- or processor-readable media include, forexample, floppy disk, flexible disk, hard disk, magnetic tape, or anyother magnetic medium, CD-ROM, any other optical medium, punch cards,paper tape, any other physical medium with patterns of holes, RAM, PROM,EPROM, EEPROM, FLASH memory, any other memory chip or cartridge, or anyother tangible medium from which a computer or processor can read.

While not illustrated, the sampling device 100 may include one or moreelements operable to deflect or otherwise position the emitted orreceived electromagnetic energy. The elements may, for example, includeone or more optical elements, for example lens assemblies, mirrors,prisms, diffraction gratings, etc. For example, the optical elements mayinclude an oscillating mirror, rotating polygonal mirror or prism, orMEMS micro-mirror that oscillates about one or more axes. The elementsmay, for example, include one or more other elements, for examplepermanent magnets or electromagnets such as those associated withcathode ray tubes and/or mass spectrometers.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet, including butnot limited to: U.S. Pat. Nos. 7,996,173; 8,081,304; and 8,076,630; U.S.Provisional Patent Application Serial Nos.: 61/760,527, filed Feb. 4,2013; 60/623,881, filed Nov. 1, 2004; 60/732,163, filed Oct. 31, 2005;60/820,938, filed Jul. 31, 2006; 60/834,662, filed Jul. 31, 2006;60/834,589, filed Jul. 31, 2006; 60/871,639, filed Dec. 22, 2006;60/883,312, filed Jan. 3, 2007; 60/890,446, filed Feb. 16, 2007;61/538,617, filed Sep. 23, 2011; 61/760,527, filed Feb. 4, 2013;61/597,586, filed Feb. 10, 2012; 61/597,593, filed Feb. 10, 2012; and61/767,716, filed Feb. 21, 2013, are incorporated herein by reference,in their entirety. Aspects of the embodiments can be modified, ifnecessary, to employ systems, circuits and concepts of the variouspatents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A sampling device, comprising: a housing; a sample chamber in thehousing, the sample chamber sized and dimensioned to receive a samplecuvette at least partially therein, the sample chamber having at leastone opaque wall and at least a first aperture and a second aperturepositioned at least partially across at least a portion of the samplechamber from the first aperture, the first and the second aperturetransmissive of electromagnetic energy of at least some wavelengths inan optical portion of the electromagnetic spectrum; a plurality ofemitters received in the housing, each of the emitters selectivelyoperable to emit electromagnetic energy in a respective range ofwavelengths toward and through the first aperture of the sample chamber,the ranges of wavelengths of at least some of the emitters differentfrom the ranges of wavelengths of others of the emitters; at least oneprimary sampling sensor positioned to receive electromagnetic energyemitting from the sample chamber via the second aperture; and at leastone calibration sensor positioned to receive electromagnetic energyemitted by at least one of the emitters, substantially free ofelectromagnetic energy emitting, if any, from the sample chamber.
 2. Thesampling device of claim 1 further comprising a calibration printedcircuit board (PCBA) having a slit opposed to the emitters, and the atleast one calibration sensor includes at least a first calibrationsensor positioned to one side of the slit and at least a secondcalibration sensor positioned to another side of the slit, the otherside of the slit disposed across the slit from the first side of theslit.
 3. The sampling device of claim 2 wherein the emitters are allaligned with the slit.
 4. The sampling device of claim 1 wherein the atleast one calibration sensor is positioned at least adjacent a firstportion of the sample chamber opposed to the emitters.
 5. The samplingdevice of claim 3 wherein the emitters are carried by an emitter circuitboard, the emitter circuit board spaced from the sample chamber opposedto the first aperture.
 6. The sampling device of claim 5 wherein atleast one of the primary sampling sensors is carried by a direct sensorcircuit board, the direct sensor circuit board spaced from the samplechamber opposed to the second aperture.
 7. The sampling device of claim1 wherein the sample chamber includes a third aperture, the thirdaperture positioned at least partially across the sampling chamber fromboth the first and the second apertures, and the at least one primarysampling sensor includes at least a first primary sampling sensorpositioned to receive electromagnetic energy emitting from the samplingchamber via the second aperture and at least a second primary samplingsensor positioned to receive electromagnetic energy emitting from thesampling chamber via the third aperture.
 8. The sampling device of claim7 wherein the second aperture is diametrically opposed across the samplechamber from the first aperture and the third aperture is non-collinearwith an optical axis that extends between the first and the secondapertures.
 9. The sampling device of claim 8 wherein the third apertureis positioned along an axis perpendicular to the optical axis thatextends between the first and the second apertures.
 10. The samplingdevice of claim 7 wherein the emitters are carried by an emitter circuitboard, the emitter circuit board spaced from the sample chamber opposedto the first aperture, at least the first primary sampling sensors arecarried by a direct sensor circuit board, the direct sensor circuitboard spaced from the sample chamber opposed to the second aperture, andat least the second primary sampling sensors are carried by an indirectsensor circuit board, the indirect sensor circuit board spaced from thesample chamber opposed to the third aperture to capture electromagneticenergy scattered from the sample chamber.
 11. The sampling device ofclaim 1, further comprising: a biasing member that biases at least thesample cuvette outwardly from the housing.
 12. The sampling device ofclaim 1 wherein the respective ranges of wavelengths of at least two ofthe emitters at least partially overlap.
 13. The sampling device ofclaim 1, further comprising: the sample cuvette sized and dimensioned tobe at least partially received by the sample chamber, at least a portionof the sample cuvette transmissive to at least some of the wavelengthsof electromagnetic energy emitted by the emitters.
 14. The samplingdevice of claim 1 wherein the optical portion of the electromagneticspectrum extends from near-infrared through near-ultraviolet.
 15. Thesampling device of claim 1, further comprising: at least one portproviding flow through fluid communication with the cuvette.
 16. Thesampling device of claim 1, further comprising: at least one controlsubsystem communicatively coupled to the emitters, the primary samplingsensors; and the calibration sensors; and at least one temperaturesensor communicatively coupled to the at least one control subsystem,wherein the at least one control subsystem controls operation based atleast in part on information from both the calibration sensors and theat least one temperature sensor.
 17. The sampling device of claim 16wherein the at least one control subsystem calibrates an output valuebased at least in part on information from both the calibration sensorsand the at least one temperature sensor.
 18. The sampling device ofclaim 16 wherein the at least one control subsystem calibrates a drivesignal supplied to at least one of the emitters based at least in parton information from both the calibration sensors and the at least onetemperature sensor.
 19. A sampling device, comprising: a housing; asample chamber in the housing, the sample chamber sized and dimensionedto receive a sample cuvette at least partially therein, the samplechamber having at least one opaque wall and at least a first aperture, asecond aperture positioned at least partially across at least a portionof the sample chamber from the first aperture, and a third aperture, thethird aperture positioned at least partially across the sampling chamberfrom both the first and the second apertures, the first, the second, andthe third apertures transmissive of electromagnetic energy of at leastsome wavelengths in an optical portion of the electromagnetic spectrum;a plurality of emitters received in the housing, each of the emittersselectively operable to emit electromagnetic energy in a respectiverange of wavelengths toward and through the first aperture of the samplechamber, the ranges of wavelengths of at least some of the emittersdifferent from the ranges of wavelengths of others of the emitters; atleast one direct primary sampling sensor positioned to receiveelectromagnetic energy emitting from the sampling chamber via the secondaperture and not by the first or the third apertures; and at least oneindirect primary sampling sensor positioned to receive electromagneticenergy emitting from the sampling chamber via the third aperture and notby the first or the second apertures.
 20. The sampling device of claim19 wherein the second aperture is diametrically opposed across thesample chamber from the first aperture.
 21. The sampling device of claim20 wherein the third aperture is non-collinear with an optical axis thatextends between the first and the second apertures.
 22. The samplingdevice of claim 20 wherein the third aperture is perpendicular to anoptical axis that extends between the first and the second apertures.23. The sampling device of claim 19 wherein the emitters are carried byan emitter circuit board, the emitter circuit board spaced from thesample chamber opposed to the first aperture, at least the first primarysampling sensor is carried by a direct sensor circuit board, the directsensor circuit board spaced from the sample chamber opposed to thesecond aperture, and at least the second primary sampling sensors iscarried by an indirect sensor circuit board, the indirect sensor circuitboard spaced from the sample chamber opposed to the third aperture tocapture electromagnetic energy scattered from the sample chamber. 24.The sampling device of claim 19, further comprising: at least onecalibration sensor positioned to receive electromagnetic energy emittedby at least one of the emitters, substantially free of electromagneticenergy emitting, if any, from the sampling chamber.
 25. The samplingdevice of claim 24, further comprising: at least one control subsystemcommunicatively coupled to the emitters, the primary sampling sensors;and the calibration sensors; and at least one temperature sensorcommunicatively coupled to the at least one control subsystem, whereinthe at least one control subsystem controls operation based at least inpart on information from both the calibration sensors and the at leastone temperature sensor.
 26. The sampling device of claim 25 wherein theat least one control subsystem calibrates an output value based at leastin part on information from both the calibration sensors and the atleast one temperature sensor.
 27. The sampling device of claim 19,further comprising: a biasing member that biases at least the samplecuvette outwardly from the housing.
 28. The sampling device of claim 19wherein the respective range of wavelengths of at least two of theemitters at least partially overlap.
 29. The sampling device of claim19, further comprising: the sample cuvette sized and dimensioned to beat least partially received by the sample chamber, at least a portion ofthe sample cuvette transmissive to at least some of the wavelengths ofelectromagnetic energy emitted by the emitters.
 30. The sampling deviceof claim 19 wherein the optical portion of the electromagnetic spectrumextends from near-infrared through near-ultraviolet.
 31. The samplingdevice of claim 19, further comprising: at least one port providing flowthrough fluid communication with the cuvette.
 32. The sampling device ofclaim 22 wherein a change in electromagnetic energy intensity emittingfrom the sampling chamber via the third aperture is indicative of atime-varying process occurring in the sample.